.nav {
  display:flex;
  height: 50px;
  width: 100%;
  align-items: center;
  justify-content: space-between;
}
.nav a{
  display:block;
  text-align:center;
  flex: 1;
  line-height: 50px;
}
.nav a.active{
  background-color:aliceblue;
  color:#000;
}